Lexical Differences and comprehension

Even in common English among Americans, there are often lexical differences that hinder comprehension. For example, sometimes I'll use the word "pop" for "soda". Some of my friends were confused about what "pop" even meant and they had no idea that I was talking about soda. I found this really interesting because I say soda half the time, and people at home will get slightly confused and say they never use the word soda.
There are a lot more lexical differences between American English and British English. I have seen a few of these lexical differences here at Stanford that have confused some people at times. I was talking to a kid about football, and since he was from England, he thought I was talking about soccer. So, for the next few minutes, he was slightly confused and then realized I was talking about "American Football" as he called it.
There are also lexical differences between people who speak English as a second language and those who don't. Each foreign language often has it's own typical lexical differences found in English. For example, my mom is a native Spanish speaker and will often say things like "feets" instead of "feet". This has nothing to do with her ability to pronounce "feet", it just comes from the fact that in Spanish, feet is made plural with an "s", just as many other words are in both Spanish and English. We have corrected her multiple times, it just seems to be an instinct. This hasn't really caused any problems with comprehension, just a bit of embarrassment for her.
Often these lexical differences do not affect language comprehension that much, they simply stop the conversation for a bit because the issue often deals with just one or two words in the sentence. The context of the sentence often resolves these misunderstandings quickly.
I found lexical differences to be really funny at times, they are a point of conversation at times. Overall, I found lexical differences really fun to talk about.